2015-01-07 14:45:11

by Arik Nemtsov

Subject: [PATCH v3] mac80211: add TDLS supported channels correctly

The function adding the supported channels IE during a TDLS connection had
several issues:
1. If the entire subband is usable, the function exitted the loop without
adding it
2. The function only checked chandef_usable, ignoring flags like RADAR
which would prevent TDLS off-channel communcation.
3. HT20 was explicitly required in the chandef, while not a requirement
for TDLS off-channel.

Signed-off-by: Arik Nemtsov <[email protected]>
Reviewed-by: Emmanuel Grumbach <[email protected]>
---
net/mac80211/tdls.c | 26 +++++++++++++++++++++-----
1 file changed, 21 insertions(+), 5 deletions(-)

diff --git a/net/mac80211/tdls.c b/net/mac80211/tdls.c
index 55ddd77..9b789c6 100644
--- a/net/mac80211/tdls.c
+++ b/net/mac80211/tdls.c
@@ -68,17 +68,24 @@ ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
ch = ieee80211_get_channel(sdata->local->hw.wiphy, i);
if (ch) {
/* we will be active on the channel */
- u32 flags = IEEE80211_CHAN_DISABLED |
- IEEE80211_CHAN_NO_IR;
cfg80211_chandef_create(&chandef, ch,
- NL80211_CHAN_HT20);
- if (cfg80211_chandef_usable(sdata->local->hw.wiphy,
- &chandef, flags)) {
+ NL80211_CHAN_NO_HT);
+ if (cfg80211_reg_can_beacon(sdata->local->hw.wiphy,
+ &chandef,
+ sdata->wdev.iftype)) {
ch_cnt++;
+ /*
+ * check if the next channel is also part of
+ * this allowed range
+ */
continue;
}
}

+ /*
+ * we've reached the end of a range, with allowed channels
+ * found
+ */
if (ch_cnt) {
u8 *pos = skb_put(skb, 2);
*pos++ = ieee80211_frequency_to_channel(subband_start);
@@ -89,6 +96,15 @@ ieee80211_tdls_add_subband(struct ieee80211_sub_if_data *sdata,
}
}

+ /* all channels in the requested range are allowed - add them here */
+ if (ch_cnt) {
+ u8 *pos = skb_put(skb, 2);
+ *pos++ = ieee80211_frequency_to_channel(subband_start);
+ *pos++ = ch_cnt;
+
+ subband_cnt++;
+ }
+
return subband_cnt;
}

--
2.1.0

2015-01-14 08:34:57

by Johannes Berg

Subject: Re: [PATCH v3] mac80211: add TDLS supported channels correctly

On Wed, 2015-01-07 at 16:45 +0200, Arik Nemtsov wrote:
> The function adding the supported channels IE during a TDLS connection had
> several issues:
> 1. If the entire subband is usable, the function exitted the loop without
> adding it
> 2. The function only checked chandef_usable, ignoring flags like RADAR
> which would prevent TDLS off-channel communcation.
> 3. HT20 was explicitly required in the chandef, while not a requirement
> for TDLS off-channel.

Applied.

johannes